JP5026187B2 - Radio system and mobile station - Google Patents

Description

The present invention relates to a radio system that causes a mobile station to identify a source base station and switch a radio CH when transmitting a radio signal from a base station to a mobile station using an SCPC digital radio system, and the radio system And a mobile station using

In general, a digital radio system uses a single-channel simple carrier (SCPC) method in which one carrier is assigned to each channel for transmitting data such as voice and text. The SCPC digital radio system is shown in, for example, a narrowband digital communication system standard ARIB STD-T61.
Hereinafter, a method in which a mobile station using the SCPC digital wireless system switches the wireless CH will be described.
The mobile station determines that the wireless CH needs to be switched when the received electric field strength of the wireless CH in the wireless signal being used is lower than the reference level. At that time, the mobile station, for example, switches to another plurality of radio CHs that are registered in the mounted radio and not used, and measures the received electric field strength of each radio CH. The mobile station selects and switches the wireless CH having the highest received electric field strength among the measured values. With this method, the mobile station always uses a wireless CH with a high received electric field strength.

Next, the conventional switching method described above will be briefly described with reference to FIG.
The base station 3a and the base station 3b have the same digital radio system, and the base station 3d has a digital radio system different from the base stations 3a and 3b. The mobile station 4a transmits / receives a radio signal to / from one of the base station 3a and the base station 3b, and performs radio communication with a management unit (not shown) connected to the base station 3a and the base station 3b. .

  For example, when the management unit and the mobile station 4a perform radio communication, the base station 3a transmits and receives radio signals to and from the mobile station 4a using radio signals F1 and f1 of the radio CH1. Further, for example, when the management unit and the mobile station 4a perform radio communication, the base station 3b uses the radio signals F1 and f1 of the radio CH2 having a frequency band different from that of the radio CH1, and transmits and receives radio signals to and from the mobile station 4a. In this way, the base station 3a and the base station 3b transmit and receive radio signals to and from the mobile station 4a using different radio channels. The base station 3d uses the radio signal F1 of the radio CH1, which is the same radio CH as the base station 3a. Since the mobile station 4a performs radio communication with the management unit via the base stations 3a and 3b, the mobile station 4a does not perform the radio communication via the base station 3d having a different digital radio system (the mobile station 4a transmits a radio signal from the base station 3d). Received but not used). The mobile station 4a transmits / receives a radio signal to / from the base station 3a or the base station 3b by properly using the radio CH1 and the radio CH2, and performs radio communication with the management unit. For example, when the mobile station 4a transmits and receives radio signals to and from the base station 3a, the mobile station 4a selects the radio CH1.

  Here, in the wireless CH arrival areas 5a, 5b, and 5d of the base stations 3a, 3b, and 3d, a part of them overlaps, and this overlapping area is defined as an overlapping area 5f. It is assumed that the mobile station 4a is arranged in the overlapping area 5f. At this time, the mobile station 4a reaches the radio CH1 in the radio signal transmitted from the base stations 3a and 3d and the radio CH2 in the radio signal transmitted from the base station 3b, but the mobile station 4a uses the radio CH1. It is assumed that wireless communication is performed with the management unit via the base station 3a.

  In this state, “for example, the radio signal F1 of the radio CH1 is not received from the base station 3d and the radio communication with the base station 3a is stopped due to the failure of the base station 3a (factor A)” or “the mobile station 4a Moves out of the area of the station 3a (outside the wireless CH1 arrival area 5a), moves into the area of the base station 3b (outside the wireless CH2 arrival area 5b), and moves out of the base station 3d (outside the wireless CH1 arrival area 5d) When any of (Factor B) occurs, the received electric field strength of the wireless CH 1 being used decreases below the reference level. The mobile station 4a cannot receive a radio signal from the base station 3a. Therefore, the mobile station 4a determines that the radio CH in the radio signal to be used needs to be switched from the radio CH1 to the radio CH2.

  Therefore, the mobile station 4a measures the reception electric field strength of the radio CH2, and if it is determined that the reception electric field strength of the radio CH2 is higher than the reference level, the mobile station 4a switches the radio CH in the radio signal to be used to the radio CH2, Wireless communication is performed with the management unit via the base station 3b.

For example, Patent Document 1 discloses such an SCPC digital wireless system. This digital radio system prevents interference (interference) of received signals having the same frequency.
JP 2003-134556 A

  However, the wireless CH transmission area of one base station that transmits the wireless CH and the wireless CH having the same frequency band as the frequency band of the wireless CH are transmitted, and the other having a digital wireless system different from the one base station. The conventional switching method described above does not function in overlapping areas in the wireless CH reach area of the base station. Therefore, there arises a problem that the mobile station cannot wirelessly communicate with a base station that wants to perform wireless communication indefinitely.

  For example, as shown in FIG. 8, when the mobile station 4a selects the wireless CH1 in the overlapping area 5f, the wireless CH1 in the wireless signal transmitted from the base station 3a and the wireless CH1 in the wireless signal transmitted from the base station 3d are overlapped. Since interference occurs at 5f, the wireless CH1 in the wireless signal transmitted from the base station 3d is also received.

  In this state, “for example, the wireless signal F1 of the wireless CH1 can be received from the base station 3d and the wireless communication with the base station 3a is stopped due to the failure of the base station 3a (factor C)” or “the mobile station 4a 3a (outside the wireless CH1 reachable area 5a) and within the base station 3b (outside the wireless CH2 reachable area 5b) and within the base station 3d (within the wireless CH1 reachable area 5d) If any one of (Move to (Factor D)) occurs, the received electric field strength of the radio CH1 in the radio signal used in the base station 3a falls below the reference level. Then, the mobile station 4a cannot receive the radio signal from the base station 3a. Therefore, the mobile station 4a needs to switch the wireless CH in the wireless signal to be used to the wireless CH2.

  That is, the mobile station 4a must switch the wireless CH in the wireless signal to be used to the wireless CH2 when the above-described factor C or factor D occurs. However, at this time, since the reception field strength of the radio CH1 of the base station 3d is maintained higher than the reference level, the mobile station 4a can receive the radio CH1 in the radio signal of the base station 3d. Therefore, the mobile station 4a determines that it is not necessary to switch the wireless CH1 whose received electric field strength is higher than the reference level, and enters a state in which neither the base station 3a nor the base station 3b performs wireless communication.

Therefore, in the present invention, in view of the above circumstances, the received radio field strength of a radio channel from a desired SCPC digital radio system is reduced, and the same radio channel having a high received electric field strength is obtained from a radio system different from this digital radio system. Even if it is received, based on the identifier stored in the wireless CH, it is determined that the wireless system is different, and a wireless system from a desired digital wireless system having a high received electric field strength is identified and switched, and a mobile station The purpose is to provide.

In order to achieve the object, the present invention is a radio system including a plurality of base stations and a mobile station that performs radio communication with the base station, and the base station transmits a radio signal including voice data to the base station. The mobile station stores and transmits information indicating a station, and the mobile station receives the radio signal from the base station, a storage unit that stores the information indicating the base station, and a received electric field of the radio signal. A first discriminating unit that discriminates whether or not the strength is lower than a reference value set in advance, and when the first discriminating unit discriminates that the received electric field strength is lower than the reference value; A switching unit that switches all the received radio signals, and the base station stored in the radio signal received by the receiving unit in each radio channel of all the radio signals switched by the switching unit. Before showing the station A second determination unit for determining whether information is registered in the storage unit; and the second determination unit determines that the information indicating the base station is registered in the storage unit; and And a specifying unit that specifies the radio signal determined by the first determining unit that the received electric field intensity is highest than the reference value, and the switching unit is specified by the specifying unit Provided is a radio system characterized by switching to the radio signal.
In order to achieve the object, the present invention is a mobile station that performs radio communication with a plurality of base stations using radio signals including audio data, and stores information indicating the base stations transmitted from the base station. A receiving unit that receives the radio signal, a storage unit that stores the information indicating the base station, and whether or not the received electric field strength of the radio signal is lower than a predetermined reference value. And a switching unit that switches all the received radio signals when the first determination unit determines that the received electric field strength is lower than the reference value. In each radio channel in all the radio signals switched by, it is determined whether or not the information indicating the base station stored in the radio signal received by the reception unit is registered in the storage unit 2 and the second determination unit determine that the information indicating the base station is registered in the storage unit, and the first determination unit determines the received electric field strength to be the reference value. A specifying unit that specifies the radio signal determined to be the highest, and the switching unit switches to the radio signal specified by the specifying unit.

In order to achieve the object of the present invention, the base station further comprises a setting unit configured to set the information for each base station, the radio system as described above , a mobile station, I will provide a.

In order to achieve the object of the present invention, the setting unit sets the information for each radio CH of the radio signal transmitted from the base station, and the mobile system according to the above, And provide stations .

In order to achieve the object of the present invention, the base station further includes a storage unit that stores the information in the radio signal transmitted by the base station, and the storage unit stores the information in the radio signal. When storing, the radio system and the mobile station described above are stored in the RICH, which is a part of the SCPC frame data format.

According to the present invention, the reception field strength of a radio channel from a desired SCPC digital radio system is reduced, and even if the same radio channel having a high reception field strength is received from a radio system different from this digital radio system. Distinguishing from a different wireless system based on an identifier stored in a wireless CH, providing a wireless system for switching from a desired digital wireless system having a high received electric field strength, and a mobile station Can do.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The first embodiment will be described with reference to FIGS. 1 to 7, the same parts as those in FIG. 8 described above are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 1 is a schematic configuration diagram illustrating a transmission source base station identification switching system that identifies a transmission source base station (hereinafter referred to as a transmission source base station) that transmits a radio signal and switches to the radio signal when switching the radio signal. It is. This transmission source base station specific switching system performs radio communication by transmitting and receiving radio signals between the base station and the mobile station using, for example, the SCPC method. In this SCPC system, for example, a narrowband digital communication system standard (ARIB STD-T61) is set. As a result, the data frame data format and connection procedure are determined during wireless communication.

  1 differs from FIG. 8 in that it has a management unit 1, a circuit switching unit 2 (2a, 2b, 2c) that relays the management unit 1 and each base station, and the same digital radio system as the base stations 3a, 3b. The base station 3c is provided. It is assumed that the base station 3c transmits a plurality of radio signals F1 having different frequency bands (radio CH3 and 4). It is assumed that a part of the wireless CH3, 4 reach area 5c in the radio signal F1 of the base station 3c overlaps the overlapping area 5f. Although three base stations 3 (3a, 3b, 3c) having the same digital radio system are described, this number is not limited.

For example, it is assumed that a plurality of mobile stations 4a, 4b, 4c, which are taxis, for example, are arranged in the wireless CH1 reach area 5a indicating the area of the base station 3a. Therefore, for example, the radio CH1 in the radio signal F1 transmitted from the base station 3a reaches the mobile station 4b. The mobile station 4a arranged in the overlapping area 5f includes a radio CH1 in the radio signal F1 transmitted from the base station 3a and the base station 3d, a radio CH2 in the radio signal F1 transmitted from the base station 3b, and a base station The radio channels 3 and 4 in the radio signal F1 transmitted from 3c arrive. In each wireless CH reach area and overlapping area 5f, the received electric field strength of the wireless CH in each wireless signal F1 corresponds to the distance from the mobile station 4a to the base station as shown in FIG.
For example, the management unit 1 wirelessly communicates data such as voice information, text information, and image information with the mobile station 4 via the circuit switching unit 2 and the base station 3 through the circuit switching unit 2 and the base station 3. And a wireless console for communication). The wireless console wirelessly transmits data having instructions to the mobile station 4a, for example, by wireless CH1 or mail via the circuit switching unit 2a and the base station 3a, and transmits a wireless signal f1 transmitted from the mobile station 4a to the base station 3a And the data transmitted from the mobile station 4a and stored or displayed.

  The circuit switching unit 2 transmits the data transmitted from the management unit 1 to the base station 3 connected to the circuit switching unit 2. The circuit switching unit 2 receives the data transmitted from the mobile station 4 via the base station 3 and transmits the received data to the wireless console.

The base station 3 transmits the data transmitted from the circuit switching unit 2 as a radio signal F1 to the mobile station 4 arranged in the wireless CH reach area, and the data transmitted from the mobile station 4 as the radio signal f1 to the circuit switching unit. 2 to send. The wireless signal F1 is, for example, a polling signal or an operating wave, and the wireless signal f1 is, for example, a polling response signal or an operating wave that responds to the polling signal.
As shown in FIG. 2, when transmitting data as a radio signal F1 to the mobile station 4, for example, the base station 3 sets an identifier (base station ID), which is first information indicating the base station, for each base station. A setting unit 30 is provided. This identifier has a base station number that causes the mobile station 4 to identify the source base station that is the base station 3 that has transmitted the radio signal F1. Therefore, the identifier differs depending on each base station that transmits the radio signal F1, as shown in FIG. Specifically, the setting unit 30 sets an identifier for each radio CH in the radio signal F1. Therefore, the setting unit 30 sets an identifier for each radio channel when transmitting a plurality of radio signals F1 having different frequency bands (radio channels 3 and 4) as in the base station 3c, for example. The set identifier may be stored in a storage unit (not shown).

The base station 3 includes a first storage unit 31 that stores an identifier in the radio signal F1 transmitted by the base station 3, a processing unit 32 that performs processing to be described later on the radio signal F1 in which the identifier is stored, A transmission / reception unit 33 for transmitting / receiving the radio signals F1, f1 is provided.
The first storage unit 31 is a channel (wireless information channel) for transmitting the above-described data in order to maintain a wireless line when storing the identifier in the wireless signal F1, and is a part of the SCPC frame data format. The identifier is stored in “RICH” (Radio Information Channel).

  In the base station 3, “RICH” is generally set to 17 bits, for example, as shown in FIG. In “RICH”, a 9-bit area is divided into 2 bits, 3 bits, 3 bits, and 3 bits in advance, and the first storage unit 31 specifies specific information that specifies the type of the radio signal F1 and the like. Are stored in advance. Therefore, the first storage unit 31 stores the identifier in the remaining 6-bit area. The first storage unit 31 stores identifiers in all 6-bit areas as shown in FIG. 3, but the present invention is not limited to this. For example, the first storage unit 31 may store the identifier in a 3-bit area and store other information in the remaining 3-bit area.

  As shown in FIG. 6 to be described later, the identifier differs depending on, for example, the wireless CH1 in the wireless signal F1 transmitted from the base station 3a and the wireless CH2 in the wireless signal F1 transmitted from the base station 3b. For example, when the identifier is stored in a 6-bit area, for example, the base station number of the former identifier is set by the setting unit 30 as “000001”, and the base station number of the latter identifier is set by the setting unit 30 as “0000010”. Is done. Further, the identifier is different between the radio CH3 in the radio signal F1 transmitted from the base station 3c and the radio CH4 in the radio signal F1 transmitted from the base station 3c. For example, when the identifier is stored in a 6-bit area, for example, the base station number of the former identifier is set by the setting unit 30 as “000100”, and the base station number of the latter identifier is set by the setting unit 30 as “000101”. Is done.

  The processing unit 32 performs CRC processing for error detection on the “RICH” storing the identifier, inserts and adds fixed bits, and performs error correction coding using, for example, a convolutional coding method Processing is performed to convert the frame data into a 56-bit frame data format, and interleave processing is performed to distribute the data in a predetermined cycle.

Further, the processing unit 32 adds “LP + R”, “Pa”, “TCH”, “SW”, and “undefined area” to “RICH” having an identifier and converted to 56 bits, for example, as shown in FIG. To generate a frame data format. The numerical values shown in FIG. 4 indicate the number of bits set in advance.
“LP + R” is the time allocated for the training period of the linearizer and the transient response (ramp up, ramp down) of the burst wave. “Pa” is a preamble signal. “TCH” is a traffic channel and transmits voice data. “SW” is a synchronization word (Sync Word).

The transmission / reception unit 33 has the identifier stored by the first storage unit 31 in “RICH”, transmits the radio signal F1 using the frame data format described above to the mobile station, and receives the radio signal f1 from the mobile station 4 Receive.
As shown in FIG. 5, the mobile station 4 includes a transmission / reception unit 41 that transmits and receives the radio signals F1 and f1 and a display that displays character information, image information, and the like that are included in the radio signal F1 described above and transmitted from the radio console. And an output unit 43 that outputs audio information and the like.

  The mobile station 4 is equipped with a transmission source base station identification switching device as shown in FIG. The transmission source base station identification switching device includes a control unit 44, a storage unit 45, a second storage unit 46, a detection unit 47, a first determination unit 48, a second determination unit 49, A specifying unit 50 and a switching unit 51 are provided, and the control unit 44 includes a storage unit 45, a second storage unit 46, a detection unit 47, a first determination unit 48, and a second determination unit 48. The determination unit 49, the specifying unit 50, the switching unit 51, the transmission / reception unit 41, the display unit 42, and the output unit 43 are controlled.

The storage unit 45 stores a reference value (reference level) having a desired value that is a threshold value for the received electric field strength of the wireless CH in the wireless signal F1.
The second storage unit 46 stores the database shown in FIG. In this database, an identifier and base station information corresponding to the identifier and second information for identifying the transmission source base station based on the identifier are registered. The base station information includes, for example, base station names such as base stations 3a, 3b, and 3c, and the frequency (wireless CH) of each base station. For example, in the database, it is registered that the transmission source base station of the radio signal F1 storing the identifier “000001” is the base station 3a.

  The detection unit 47 detects the reception field strength of the wireless CH in the wireless signal F1 transmitted from each base station 3, and at this time, detects the wireless CH whose reception field strength is the highest than the reference level.

  The first determination unit 48 determines whether or not the received electric field intensity detected by the detection unit 47 is lower than the reference level stored in the storage unit 45.

  When the first determination unit 48 determines that the reception field strength of the wireless CH in the wireless signal F1 being used has decreased below the reference level, the switching unit 51 converts the wireless CH in the wireless signal F1 to be used into the reception field strength. Are switched to all other radio channels higher than the reference level.

  The switching unit 51 switches the wireless CH to be used to the wireless CH specified by the specifying unit 50 described later. When the first determination unit 48 determines that the received electric field intensity is higher than the reference level, the switching unit 51 maintains the state of receiving this wireless CH without switching the wireless CH.

The second determination unit 49 determines whether or not the base station information corresponding to the identifier stored in the radio signal F1 is registered in the database in each radio CH in all radio signals F1 switched by the switching unit 51. Determine the transmission source base station of the radio signal F1. At that time, the second determination unit 49 determines that the wireless CH in the wireless signal F1 storing the identifier not described in the database is the wireless CH in the wireless signal F1 of a different digital wireless system, and Delete from the switch destination candidates.
The identifying unit 50 identifies the wireless CH in the radio signal F1 in which the transmission source base station is determined by the second determining unit 49 and the received electric field strength is determined to be higher than the reference level by the first determining unit 48. .

  In the present embodiment, the transmission source base station is configured by the setting unit 30, the first storage unit 31, the processing unit 32, the transmission / reception unit 33, and the transmission source base station specific switching device mounted on the mobile station 4. A specific switching system is configured.

  The management unit 1 and the mobile station 4 perform data communication using the radio signals F1 and f1 via the circuit switching unit 2 and the base station 3. Further, the management unit 1 and each mobile station 4 perform data communication including, for example, a simultaneous call using the radio signals F1 and f1 via the circuit switching unit 2 and the base station 3.

  In addition, mobile stations (for example, the mobile station 4a and the mobile station 4b) arranged within the same base station 3 perform data communication including a telephone call, for example, using direct waves. Further, the mobile station 4a and the mobile station 4d arranged in the area of the base station 3b are arranged in the area of the base station 3a, and the data including, for example, a call is transmitted via the circuit switching units 2a and 2b and the base stations 3a and 3b. Communicate.

All the mobile stations 4 perform data communication by switching the radio signals F1 and f1 and direct waves.
Character information and voice information can be transmitted and received simultaneously. The base stations 3 and the circuit switching units 2 may be connected to each other.

Next, operations of the transmission source base station identification switching system and the transmission source base station identification switching device configured as described above will be described.
When the management unit 1 performs data communication with the mobile station 4a via the circuit switching unit 2a and the base station 3a, the first storage unit 31 stores “RICH” in the base station 3a as shown in FIG. An identifier is stored. The “RICH” in which the identifier is stored is subjected to the above-described processing by the processing unit 32, and is transmitted to the mobile station 4a by the transmission / reception unit 33 as a radio signal F1.

  At that time, when the mobile station 4a moves away from the base station 3a and approaches the base station 3b in the overlap area 5f, for example, the received electric field strength of the radio CH1 in the radio signal F1 transmitted from the base station 3a is shown. As shown in FIG. At that time, the first determination unit 48 determines whether or not the received electric field strength of the wireless CH 1 detected by the detection unit 47 is lower than the reference level stored in the storage unit 45.

  When the first determination unit 48 determines that the received electric field strength has fallen below the reference level, the wireless CH in the wireless signal F1 used when the mobile station 4a performs data communication with the management unit 1 is changed to the switching unit. 51 switches to the wireless CH in the other wireless signal F1 whose received electric field strength is higher than the reference level. In this case, the switching unit 51 switches from the wireless CH1 in the wireless signal F1 transmitted from the base station 3a to the wireless CH in the receivable wireless signal F1. That is, the switching unit 51 switches between the radio CH2 in the radio signal F1 transmitted from the base station 3b and the radio CH3 and 4 in the radio signal F1 transmitted from the base station 3c, and the radio signal F1 transmitted from the base stations 3b and 3c. Receive.

  At this time, the identifier is stored in the first storage unit 31 in the radio signal F1 transmitted from the base stations 3b and 3c, similarly to the radio signal F1 transmitted from the base station 3a described above. The mobile station 4a arranged in the overlapping area 5f is in a state where it can receive the radio CH1 in the radio signal F1 transmitted from the base station 3d, and therefore receives the radio signal F1 transmitted from the base station 3d. The radio signal F1 does not store an identifier because the base station 3d uses a digital radio system different from the base station 3a.

  Corresponding to the identifiers of these wireless CHs in the wireless CHs 2, 3 and 4 in the wireless signal F1 transmitted from the base stations 3b and 3c switched by the switching unit 51 and in the wireless CH1 in the wireless signal F1 transmitted from the base station 3d. Whether the base station information is registered in the database stored in the second storage unit 46 is determined by the second determination unit 49. In the database stored in the second storage unit 46, only identifiers corresponding to the radio channels 2, 3, and 4 in the radio signal F1 transmitted from the base stations 3b and 3c are registered. Therefore, the 2nd discrimination | determination part 49 discriminate | determines that a transmission origin base station is 3b, 3c from the result of referring the database based on these identifiers. In addition, the second determination unit 49 determines that the wireless CH1 transmitted from the base station 3d is the wireless CH1 of the wireless signal F1 transmitted from a different digital wireless system, and deletes it from the switching destination candidate.

  Next, the identifying unit 50 discriminates the transmission source base station (base stations 3b and 3c) by the second discriminating unit 49 and discriminates that the received electric field strength is higher than the reference level by the first discriminating unit 48. The radio channel F (one of radio channels 2, 3, 4) of the radio signal F1 is specified. The mobile station 4 moves to the overlapping area 5f and approaches the base station 3b. Therefore, the identifying unit 50 identifies that the received electric field strength of the wireless CH2 is the highest. The switching unit 51 switches the radio signal F1 used for the radio signal F1 having the radio CH2 identified by the identifying unit 50.

  As described above, the mobile station 4 of the present embodiment moves from the wireless CH1 arrival area 5a to the overlapping area 5f, for example, or the radio signal transmitted from the base station 3a due to a decrease in received electric field strength due to the factor D described above. The wireless CH1 in F1 cannot be received. At that time, even if the mobile station 4 receives the same radio CH1 as the base station 3a from the base station 3d using a digital radio system different from the base station 3a, the mobile station 4 stores the radio signal F1 in the radio signal F1. It is possible to distinguish from different digital wireless systems based on the identifiers to be deleted from the switching destination candidates. Further, when the mobile station 4 receives the radio signal F1 transmitted from the base stations 3b and 3c using the same digital radio system as the base station 3a, the mobile station 4 uses the same digital information as the base station 3a from the identifier stored in the radio signal F1. It is possible to determine that the base station uses the wireless system, and further to identify and switch the wireless CH having the highest received electric field strength.

  As a result, the mobile station 4 according to the present embodiment switches between the circuit switching unit 2 and the wireless switching channel 2 to switch to another wireless CH from the same digital wireless system even if the received electric field strength of the wireless CH used is lower than the reference level. Data communication with the management unit 1 can be performed without waste through the base station 3 without reducing the communication efficiency.

  The identifier is different for each wireless CH. Therefore, the mobile station 4 switches even with the wireless CHs (wireless CH3 and wireless CH4 in this embodiment) in a plurality of wireless signals F1 transmitted from the same base station 3 (base station 3c in this embodiment). It can be determined that the radio signal F1 is transmitted from the base station 3 using the previous digital radio system.

  Further, as the first storage unit 31 stores more identifiers in “RICH”, the base station 3 can transmit more information that can identify the source base station 3 to the mobile station 4. As a result, the mobile station 4 can more reliably determine that the received radio signal F1 is the same as the digital radio system used.

  Although the first storage unit 31 stores the identifier in “RICH”, the identifier is not necessarily limited to this. For example, the identifier may be stored in the “undefined” area of the frame data format shown in FIG.

  In addition, although the said description was limited to the description for discriminating a transmission origin base station when the mobile station 4a and the management part 1 perform data communication, it is not necessary to limit to this. For example, the same effect can be obtained when the mobile station 4b and the mobile station 4d perform data communication with the base stations 3a and 3b via the circuit switching units 2a and 2b. For example, the same effect can be obtained when the management unit 1 and the mobile stations 4a and 4b communicate with the base station 3 via the circuit switching unit 2.

  In FIG. 1, the circuit switching unit 2 and the base station 3 are independent from the management unit 1, but the management unit 1, the circuit switching unit 2, the base station 3, and the base station according to the scale of the transmission source base station specific switching system. The station 3 can also be configured integrally.

  As described above, the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment.

FIG. 1 is a schematic configuration diagram illustrating a transmission source base station identification switching system that identifies a transmission source base station that transmits a radio signal and switches to the radio signal when switching the radio signal in the present embodiment. FIG. 2 is a schematic configuration diagram schematically showing a system configuration of the base station of the present embodiment. FIG. 3 is a diagram illustrating an example of “RICH” which is a part of the transmission frame data format in the SCPC transmission source base station specific switching apparatus. FIG. 4 is a diagram illustrating an example of a transmission frame data format in the SCPC transmission source base station identification switching device. FIG. 5 is a schematic configuration diagram of the transmission source base station identification switching device of the present embodiment. FIG. 6 is a diagram showing a database in which a base station number of an identifier corresponding to a transmission source base station and a transmission source base station and a base station number of an identifier corresponding to a wireless CH transmitted to the transmission source base station are collected. It is. FIG. 7 is a diagram illustrating the relationship between the received electric field strength of the radio signal transmitted from the base station and the distance from the mobile station to the base station. FIG. 8 is a schematic configuration diagram showing conventional switching.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Management part, 2 (2a, 2b, 2c) ... Circuit switching part, 3 (3a, 3b, 3c, 3d) ... Base station, 4 ... Mobile station, 5a, 5b, 5c, 5d ... Wireless CH coverage area, DESCRIPTION OF SYMBOLS 31 ... 1st storage part, 32 ... Processing part, 33 ... Transmission / reception part, 41 ... Transmission / reception part, 42 ... Display part, 43 ... Output part, 44 ... Control part, 45 ... Memory | storage part, 46 ... 2nd storage part , 47... Detector, 48... First discriminator, 49... Second discriminator, 50.

Claims (4)

A wireless system comprising a plurality of base stations and a mobile station that performs wireless communication with the base station,
The base station stores and transmits information indicating the base station in a radio signal including voice data,
The mobile station
A receiver for receiving the radio signal from the base station;
A storage unit for storing the information indicating the base station;
A first discriminating unit for discriminating whether or not the received electric field intensity of the radio signal has decreased below a reference value set in advance as desired;
A switching unit that switches all the received radio signals when the first determination unit determines that the received electric field strength is lower than the reference value;
Whether or not the information indicating the base station stored in the radio signal received by the reception unit is registered in the storage unit in each radio channel in all the radio signals switched by the switching unit. A second discriminating unit for discriminating;
The second determining unit determines that the information indicating the base station is registered in the storage unit, and the first determining unit determines that the received electric field strength is the highest than the reference value. A specifying unit for specifying the radio signal,
Comprising
The switching unit switches to the radio signal specified by the specifying unit .   If the second determination unit determines that the information indicating the base station stored in the radio signal is not registered in the storage unit, the second determination unit deletes the radio channel of the radio signal from the switching destination candidates The wireless system according to claim 1.   A mobile station that performs radio communication with a plurality of base stations by radio signals including audio data,
  A receiver that receives the radio signal in which information indicating the base station transmitted from the base station is stored;
  A storage unit for storing the information indicating the base station;
  A first discriminating unit for discriminating whether or not the received electric field intensity of the radio signal has decreased below a reference value set in advance as desired;
  A switching unit that switches all the received radio signals when the first determination unit determines that the received electric field strength is lower than the reference value;
  Whether or not the information indicating the base station stored in the radio signal received by the reception unit is registered in the storage unit in each radio channel in all the radio signals switched by the switching unit. A second discriminating unit for discriminating;
  The second determining unit determines that the information indicating the base station is registered in the storage unit, and the first determining unit determines that the received electric field strength is the highest than the reference value. And a specifying unit for specifying the radio signal,
  The mobile station, wherein the switching unit switches to the radio signal specified by the specifying unit.   If the second determination unit determines that the information indicating the base station stored in the radio signal is not registered in the storage unit, the second determination unit deletes the radio channel of the radio signal from the switching destination candidates The mobile station according to claim 3.

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